The present invention relates to a vernier device of the digital display type for a universal parallel ruler.
With universal parallel rulers of the prior art, it has been relatively easy to read and set the scale's rotation angle so far as the fine graduations on the protractor are concerned but similar such reading and setting have been very difficult with respect to the vernier graduations which are much finer than the fine graduations on the protractor. Although it has been proposed to display rotation angles in the digital manner, such reading and setting have proved incon- veniently troublesome since the number of positions to be displayed are so many.